胶质母细胞瘤6号染色体杂合性丢失的初步研究

目的：寻找胶质母细胞瘤（GBM）6号染色体上可能存在肿瘤抑制基因的杂合性丢失（LOH）区域,为发现和定位肿瘤抑制基因（TSG）提供线索和依据。方法：应用聚合酶链反应（PCR）方法,采用荧光标记的引物及377型DNA序列自动分析仪,分析了21例GBM患者6号染色体上20个微卫星多态性标记的LOH。结果：6号染色体总的LOH检出率为47．6％（10／21）,在28．1％（81／288）能提价信息位上检测了LOH。其中,6p和6q的LOH检出率分别是28．6％（6／21）、38．1％（8／21）,在6q^tel上距短臂端粒201．1cM的微卫星位点D6S281检测到较高的LOH率（50％）,6q^16.3上D6S287的LOH率也高达50％,另外,6p^21.1-21.3上D6S276的LOH率也较高（35．3％）。结论：6号染色体分子遗传学异常改变可能在GBM的发生发展中起着重要作用,染色体6q^tel上的D6S281位点,6q^16.3上的D6S287和6p^21.1-21.3的D62S276位点所在的染色体区域可能存在与GBM相关的肿瘤抑制基因。     

10号染色体可能含有多个与胶质母细胞瘤相关的肿瘤抑制基因

目的 寻找胶质母细胞瘤（GBM）10号染色体上可能存在肿瘤抑制基因的杂合性丢失（LOH）区域,为发现和定位肿瘤抑制基因（TSG）提供线索和依据。方法 应用聚合酶链反应（PCR）方法,采用荧光标记的引物和先进的377型DNA序列自动分析仪,分析了21例GBM10号染色体上20个微卫星多态性标记的LOH。结果 在85．7％（18／21例）GBM的10号染色体上观察到LOH,在57．7％（162／281）可提供信息位点上存在LOH。10q的LOH率高于10p,分别是81．0％（17／21）、66．7％（14／21）。在下列位点或区域检测到较高的LOH率（＞60％）：10q22.3-23.3上的D10s185-D10s192间区域,10p14-15.1上的D10s591-D10s249间区域,10q24.2-26.3上的D10s1693-D10s212间区域,10p12.2-14上的D10s547位点,10q21.3上的D10537位点。结论 10号染色体可能在GBM的分子水平发病机制中发挥着重要作用,它上面的多个染色体区域可能存在与GBM相关的多个TSG。     

Loss of heterozygosity on chromosome arms 3p and 6q in microdissected adenocarcinomas of the uterine cervix and adenocarcinoma in situ

BACKGROUND: Despite the increasing frequency of adenocarcinomas of the uterine cervix, little is known regarding inactivation of tumor suppressor genes (TSGs) in this tumor type. The authors analyzed loss of heterozygosity (LOH) in 36 carcinomas of the cervix with glandular differentiation, and 5 adenocarcinoma in situ in 40 patients. METHODS: The authors analyzed samples using laser capture microdissection from archival material and DNA amplified with microsatellite markers on the following loci: 3p14.2 (D3S1234, D3S1300), 3p21.3 (D3S1029, D3S1447), 3p22-24 (D3S1537, D3S1351), 6q21-23.3 (D6S250), 6q25.1 (ESR), 6q25.2 (D6S255), 8p21 (D8S136, D8S1820), 13q12.3 (D13S220, D13S267), 17q21 (D17S579, D17S855). Eight additional markers spanning the short arm of chromosome 3 (3p12-p25) and six spanning the long arm of chromosome 6 (6q11-q27) were studied in the cases showing LOH to further define the deletion intervals. RESULTS: The frequency of allelic loss in cancers was chromosome 3p: 49% (p14.2: 35%, p21.3: 23%, p22-24: 41%), 6q: 48% (q21-23.1: 39%, q25.1: 45%, q25.2: 7%), 13q: 22%, 17q: 6%, and 8p: 18%. On chromosome arm 3p, the authors' data suggest at least two discrete areas of deletion: a proximal area between markers D3S1234 (p12) and D3S1766 (p14.2-14.3), and a second distal interval, telomeric from marker D3S4623 (p21.3). On chromosome 6q, the deletion area is between marker D6S300 (q22) and D6S255 (q25.2). Two of five preneoplastic lesions showed LOH on chromosome arm 3p, and two five showed allelic loss on chromosome arm on 6q, suggesting the genes might be inactivated early in cervical tumorigenesis. CONCLUSIONS: The authors have identified three chromosomal regions that may harbor TSGs involved in the development/progression of adenocarcinomas of the uterine cervix, 3p12-14.2, 3p21.3-pter, and 6q22-25.2. Deletions also were detected in adenocarcinoma in situ, suggesting the genes may be inactivated early in cervical tumorigenesis.     

High resolution mapping of chromosome 6 deletions in cervical cancer.

Chromosome 6 is frequently affected in different tumors. However, little information exists on chromosome 6 deletions in cervical cancer. We have studied loss of heterozygosity (LOH) and microsatellite instability (MIN) in 62 invasive squamous cell carcinomas of the cervix (CC) using 19 polymorphic microsatellite markers spanning both arms of chromosome 6 and one marker located at 5p15. We found that LOH at chromosome 6 is a common feature of cervical carcinomas: 90% (56/62) of CC had LOH at least at one locus and about 58% (36/62) had LOH on both arms of chromosome 6. The highest LOH incidence was shown in HLA region (6p21.3-6p21.1) with markers D6S273 and D6S276 in 52.7% and 45.2% of informative cases respectively. Frequent LOH on 6q was found at loci D6S311 (6q24-25. 1), D6S305 (6q26) and D6S281 (6q27-6qter) in 37.8%, 33.3% and 39.0% of informative cases respectively. There was no significant correlation observed between clinical parameters of cervical cancer (age, histologic grade, clinical stages and progression) and LOH frequency. Microsatellite instability was found in 3 out of 62 cases (4.8%) at three and more loci out of 20 tested. The study shows that several regions on 6p and 6q may harbour potential tumor-suppressor genes important for cervical cancer progression.     

Deletion of chromosome 11p15, p12, q22, q23-24 loci in human prostate cancer

Loss of heterozygosity (LOH) on chromosome 11 is frequently altered in various epithelial cancers. The present study was designed to investigate LOH on chromosome 11 in microdissected samples of normal prostatic epithelium and invasive carcinoma from the same patients. For this purpose, DNA was extracted from the microdissected normal and tumor cells of 38 prostate cancers, amplified by polymerase chain reaction PCR and analyzed for LOH on chromosome 11 using 9 different polymorphic DNA markers (D11S1307, D11S989, D11S1313, D11S898, D11S940, D11S1818, D11S924, D11S1336 and D11S912). LOH on chromosome 11 was identified in 30 of 38 cases (78%) with at least one marker. Four distinct regions of loss detected were: 1) at 11p15, at loci between D11S1307 and D11S989; 2) at 11p12, on locus D11S131 (11p12); 3) at 11q22, on loci D11S898, D11S940 and D11S1818; and 4) at 11q23-24, on loci between D11S1336 and D11S912. We found 25% of the tumors with LOH at 11p15; 39% had LOH at 11p12; 66% had LOH at 11q22; and 47% had LOH at 11q23-24. These deletions at 11p15, 11p12, 11q22 and 11q23-24 loci were not related to the stage or grade of the tumor. Int. J. Cancer 72:283–288, 1997. © 1997 Wiley-Liss, Inc.     

Identification of distinct regions of allelic loss on chromosome 13q in nasopharyngeal cancer from paraffin embedded tissues.

Our main purpose was to identify tumor suppressor gene loci on chromosome 13 responsible for nasopharyngeal cancer (NPC) development by analyzing loss of heterozygosity (LOH) and RB protein expression in paraffin embedded tissues. Normal and tumor DNA were extracted from microdissected samples, and their whole genomes were amplified using degenerate oligonucleotide primers. The polymerase chain reaction (PCR) products were analyzed by repeated amplification using primers derived from 16 microsatellite regions spanning the long arm of this chromosome. Among 50 informative cases, LOH was observed in 44 tumors. Thirty-one tumors displayed partial loss and provided an informative basis for detailed deletion mapping. Three minimal regions of loss were delineated; the first flanked by D13S120 and D13S219, the second by D13S126 and D13S119, and the third by D13S137 and 13qter. These 3 regions were linked to BRCA2 on 13q12, RB1 on 13q14, and 13q14.3-ter, respectively. Seven and 4 cases showed LOH either on 13q12 or 13q14, respectively. Nineteen cases showed LOH of both loci separately. One NPC displayed 13q12 and 13q14.3-ter LOH. RB protein expression was detectable in 76% of the cases. Ten out of 15 cases with the allelic losses limited to 13q14 showed RB protein expression. Contrasting that, 6 out of 7 cases devoid of RB protein expressions showed 13q14LOH. In conclusion, 13qLOH, involving 3 tumor suppressor gene loci, appears to be a frequent genetic event occurring during NPC development. However, other tumor suppressor genes besides RB1, may be responsible for the majority of 13q14LOH.     

肝外胆管癌染色体3p21.3区段微卫星不稳定和杂合性缺失分析

目的：研究肝外胆管癌染色体3p21．3区段的微卫星不稳定性（MSI）度杂合性缺失（LOH），探讨染色体3p21．3区段遗传不稳定性与肝外胆管癌的发生发展的关系，定位该区段上肝外胆管癌相关肿瘤基因。方法：用PCR-SSCP方法检测24例肝外胆管癌染色体3p21.3区段上D3S1568，D3S1621，D3S1578和D3S1289四个微卫星位点的MSI和LOH发生率．分析其与临床病理因素之间的关系。结果：24例肝外胆管癌组织中．四个微卫星位点的MSI和LOH平均发生率分别为7．23％和15．63％。其中D3S1621位点的LOH最高（45.83％．11／24），并与TNM分期、是否伴有局部／淋巴结转移相关（p〈0．05）。结论：染色体3p21．3区段D3S1621住点高频率杂合性缺失．提示3p21．3区段可能定位有肝外胆管癌的候选抑癌基因，并在肝外胆管癌的发生发展过程中发挥重要作用。     

CHROMOSOME 3 MAY HARBOR MULTIPLE TUMOR SUPPRESSOR GENES ASSOCIATED WITH PRIMARY GLIOBLASTOMA MULTIFORME

Glioblastoma multiforme (GBM), the most malignant type of glioma, is the most common primary brainneoplasm. Although comprehensive therapeutic measures are applied, the prognosis of GBM remains dismal with a median post-treatment survival of less than one year.Modern molecular genetics has demonstrated thatabnormal alterations of tumor suppressor genes (TSGs) and oncogenes are the major mechanisms responsible for the initiation and progression of this malignant tumor.Identifying of related…     

显微切割鼻咽癌组织16号染色体杂合性缺失的研究

目的：研究鼻咽癌中１６号染色体的缺失情况。方法：采用显微切割的方法获取肿瘤组织,然后用ＰＣＲ的方法以１６号染色体上的８对引物对３８例鼻咽癌进行分析。结果：３８例鼻咽癌组织中所有标本至少有一个位点出现有杂合笥缺失,其中Ｄ１６Ｓ５３３出现杂合性缺失的频率最高,占８６．１％（３１／３３）,此外,杂合性缺失频率超过５０％的有引物Ｄ１６Ｓ３９８、Ｄ１６Ｓ３００和Ｄ１６Ｓ４２０。分别占７８．８％（２６／３３）     

Loss of Heterozygosity for Loci on Chromosome Arms 1p and 10q in Oligodendroglial Tumors: Relationship to Outcome and Chemosensitivity

Oligodendroglial tumors frequently have deletions of chromosomal loci on 1p and 19q. Loss of heterozygosity (LOH) of chromosome 10 may be a negative prognostic factor. We reviewed 23 patients with oligodendroglial tumors, to evaluate the frequency of 1p and 10q LOH and correlate with clinical outcome. Three loci (D1S402, D1S1172, MCT118) on 1p and 2 loci (D10S520 and D10S521) on 10q were analyzed for LOH using PCR techniques. Sixteen oligodendrogliomas (6 low grade and 10 anaplastic) and 7 oligoastrocytomas (1 low grade and 6 anaplastic) were studied. Overall 14/22 (64%) showed 1p LOH and 7/23 (30%) showed 10q LOH. Of 7 patients with some response to chemotherapy, all showed 1p LOH and none had 10q LOH. Of 5 patients with stable or progressive disease, 1 had 1p LOH and 2 showed 10q LOH. The presence of 1p LOH was significantly associated with response to chemotherapy (p = 0.02). Median progression free survival (PFS) was 31 months for 1p intact patients and 118 months for the 1p LOH group (p = 0.014). Median PFS for 10q LOH patients was 31 and 118 months for patients with intact chromosome 10 (p = 0.016). 1p LOH is a predictor of response to chemotherapy and a good prognostic factor. 10q LOH is less common in oligodendroglial tumors but predicts for worse outcome. Molecular genotyping of oligodendroglial tumors is recommended as part of the standard diagnostic workup.     

Localization of a tumour-suppressor gene associated with human oral cancer on 7q31.1

To search for the existence of a tumour-suppressor gene (TSG) associated with oral squamous cell carcinoma (SCC), PCR analysis of microsatellite polymorphisms corresponding to 14 loci which map to chromosome 7q21.3-qter was performed to screen 35 patients with oral SCC for loss of heterozygosity (LOH). LOH was observed in at least one of the loci in 19 of 34 (55.9%) informative cases. Among the loci tested, frequent LOH was restricted at D7S522 on chromosome 7q31.1, which was measured within 1 cM. Furthermore, we detected microsatellite instability (MI) in 11 of 35 (31.4%) cases tested. Our observations indicate that alterations of chromosome 7q are associated with oral SCC tumorigenesis and that 7q31.1 might harbour at least one putative TSG. Int. J. Cancer 75:671–674, 1998.© 1998 Wiley-Liss, Inc.     

原发性肝癌8号和16号染色体杂合子丢失的研究

目的:分析人肝细胞肝癌(HCC)组织中染色体8和16部分染色体片段的杂合子丢失及与临床病理关系,初步筛选HCC相关的抑癌基因,为HCC的早期诊断、预后预警提供可能的新分子标记物.方法:应用聚合酶链反应-变性聚丙烯酰胺凝胶-银染法分析45例HCC组织标本中分别位于染色体8和16上的具有高度多态性微卫星位点的杂合性丢失(LOH)状态.结果:发生LOH的总频率为68.89％ (31/45),其中D16S511位点的LOH发生率最高为53.33％ (24/45),其次是D8S261( 39.02％,16/41)和D8S499(34.88％,15/43).结论:染色体16q23、8p22-21.3及8p12区域的LOH发生频率高,可能存在与HCC发生发展相关的新的抑癌基因,特定位点的遗传变异可能与HBV感染、临床病理恶性程度等预后因素相关.     

Loss of heterozygosity for defined regions on chromosomes 3, 11 and 17 in carcinomas of the uterine cervix.

Loss of heterozygosity (LOH) frequently occurs in squamous cell carcinomas of the uterine cervix and indicates the probable sites of tumour-suppressor genes that play a role in the development of this tumour. To define the localization of these tumour-suppressor genes, we studied loss of heterozygosity in 64 invasive cervical carcinomas (stage IB and IIA) using the polymerase chain reaction with 24 primers for polymorphic repeats of known chromosomal localization. Chromosomes 3, 11, 13, 16 and 17, in particular, were studied. LOH was frequently found on chromosome 11, in particular at 11q22 (46%) and 11q23.3 (43%). LOH on chromosome 11p was not frequent. On chromosome 17p13.3, a marker (D17S513) distal to p53 showed 38% LOH, whereas p53 itself showed only 20% LOH. On the short arm of chromosome 3, LOH was frequently found (41%) at 3p21.1. The beta-catenin gene is located in this chromosomal region. Therefore, expression of beta-catenin protein was studied in 39 cases using immunohistochemistry. Staining of beta-catenin at the plasma membrane of tumour cells was present in 38 cases and completely absent in only one case. The tumour-suppressor gene on chromosome 3p21.1 may be beta-catenin in this one case, but (an)other tumour-suppressor gene(s) must also be present in this region. For the other chromosomes studied, 13q (BRCA-2) and 16q (E-cadherin), only sporadic losses (< 15% of cases) were found. Expression of E-cadherin was found in all of 37 cases but in six cases the staining was very weak. No correlation was found between clinical and histological parameters and losses on chromosome 3p, 11q and 17p. In addition to LOH, microsatellite instability was found in one tumour for almost all loci and in eight tumours for one to three loci. In conclusion, we have identified three loci with frequent LOH, which may harbour new tumour-suppressor genes, and found microsatellite instability in 14% of cervical carcinomas.     

Frequent loss of heterozygosity on chromosome 9 in Chinese esophageal squamous cell carcinomas

Multiple and extensive alterations in chromosome 9 were detected in thirty-four esophageal squamous cell carcinoma patients, using seventeen polymorphic markers localized to chromosome 9 to detect the loss of heterozygosity (LOH) by polymerase chain reaction techniques. The LOH rates detected in this study range from 42.9 to 80.0%. Three commonly deleted regions mapping to 9p23-p22, 9q13-q22.3, and 9q34 were observed. D9S1812 LOH at 9q22.1 was significantly associated with well- and moderately-differentiated tumors; LOH at D9S768, mapping to 9q13-21.3, indicated that drinking habits are not a significant risk factor for Chinese esophagus cancer. Interestingly, no case of microsatellite instability was observed.     

Chromosome 6p21.2, 18q21.2 and human papilloma virus (HPV) DNA can predict prognosis of cervical cancer after radiotherapy

Loss of heterozygosity (LOH) is one of the most important mechanisms for inactivation of tumor-suppressor genes. Studies of LOH in patients with cervical carcinoma have reported a high frequency of LOH on 3p21.3, 6p21.2, 17p13.1, and 18q21.2. Our study explored whether p53 status, human papilloma virus (HPV), and LOH on chromosome 3p21.3, 6p21.2, 17p13.1, and 18q21.2 are associated with treatment outcome in 65 patients with cervical cancer after radiotherapy. Tumors and normal DNA were analyzed by polymerase chain reaction (PCR) for genetic losses at 10 polymorphic microsatellite loci. The presence of HPV and its type were analyzed by PCR-based assay using the consensus primers for E6, E7, and L1 region. Mutations of the p53 gene were identified by a single-strand conformation polymorphism analysis. Chromosomes 3p21.3, 6p21.2, 17p13.1, and 18q21.2 were involved in the LOH in 23.1%, 41.5%%, 33.8%, and 23.1% of the tumors in our study, respectively. HPV-positive tumors were found in 73.8% of the patients and p53 mutation in 10.8%. The patients with LOH on chromosome 6p21.2 and 18q21.2 survived significantly shorter compared with those without LOH on chromosome 6p21.2 and 18q21.2 in both the overall survival (P = 0.006 and P = 0.007) and the disease-free survival (P = 0.005 and P = 0.008). The HPV-negative patients survived significantly shorter compared with the HPV-positive patients in both the overall survival (P = 0.01) and the disease-free survival (P = 0.04). According to multivariate analysis, HPV status (P = 0.0004, P = 0.01), LOH on 6p21.2 (P = 0.006, P = 0.02), and LOH on 18q21.2 (in both P = 0.01) is a significant predictor of both overall and disease-free survival time. The results of our study suggest that absence of HPV infection, LOH on 6p21.2, and LOH on 18q21.2 are the most important determinants of outcome of patients with cervical carcinoma after radiotherapy.     

Deletion mapping of chromosome 4q in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) frequently shows a loss of heterozygosity (LOH) on chromosome 4q. In order to define the commonly affected region on chromosome 4q for further positional cloning of the putative tumor suppressor gene, we carried out allelic imbalance (AI) studies in 41 HCCs using a panel of 43 microsatellite markers. Thirty-four cases (82.9%) showed AI at one or more loci. Detailed deletion mapping identified 7 independent, frequently deleted regions on this chromosome arm. These were the (1) D4S1615 locus, (2) D4S1598 locus, (3) D4S620 locus, (4) D4S1566 and D4S2979 loci, (5) D4S1617 and D4S1545 loci, (6)D4S1537 locus; and (7) from the D4S2920 to D4S2954 locus. Among these 7 frequently deleted regions, 5 were associated with tumor differentiation. Our results suggest that several putative tumor suppressor genes may be present on chromosome 4q and that the AI of chromosome 4q may play a role in the aggressive progression of HCC. Int. J. Cancer (Pred. Oncol.) 79:356–360, 1998. © 1998 Wiley-Liss, Inc.     

Loss of two new loci on chromosome 8 (8p23 and 8q12-13) in human prostate cancer

Inactivation of tumor suppressor genes due to allelic loss is thought to be an important mechanism of gene alterations in prostatic carcinogenesis. Loss of sequences on the short arm of chromosome 8 (8p) has been reported in human cancers, especially of 8p22 and 8p12-21 in prostate cancer. By using PCR analysis of polymorphic microsatellite repeat markers at four 8p loci and three 8q loci in 60 tumors, we observed deletion of sequences at two other deletion domains (8p23, and 8q12-13). There was loss in 51 of 60 cases (85%) with at least one marker. Four distinct regions of loss detected were: i) at 8p23, at locus D8S262; ii) at 8p22, on locus D8S259; iii) at 8p12, on loci D8S255 and D8S285; iv) at 8q12-13, on loci between D8S260 and D8S528. We found that 29% of the tumors showed LOH at 8p23; 19% LOH on 8p22; 54% had LOH at 8p12; and 48% had LOH at 8q12-13. There was higher frequency of LOH at 3 or more loci in samples of T3 stage (62%) as compared to T2 stage (13.3%) which suggests higher incidence of LOH in advanced stage of prostate cancer. We report deletion of two novel loci at 8p23 and 8q12-13, these regions may contain putative tumor suppressor genes in prostate cancer.     

胶质母细胞瘤3号染色体杂合性丢失的研究

目的　寻找胶质母细胞瘤 (GBM) 3号染色体上可能存在肿瘤抑制基因的杂合性丢失 (LOH)区域 ,为发现和定位肿瘤抑制基因 (TSG)提供线索和依据。方法　采用荧光标记的引物和 377型DNA序列自动分析仪 ,分析了 2 0例GBM 3号染色体上 2 3个微卫星多态性标记的LOH。结果　在 50 % (1 0 / 2 0例 )GBM的 3号染色体上观察到LOH ,在 2 5 .6 % (88/ 344)可提供信息位点存在LOH。其中 3q的LOH率明显高于 3p ,3q和 3p的LOH率分别为 50 % (1 0 / 2 0 )、35 % (7/ 2 0 )。在 3q上的下列位点检测到较高的LOH率 :3q2 2 2 3上的微卫星位点D3s1 569(35 .3 % )、3q2 4 2 7上的D3s1 61 4 (42 .9% ) D3s1 565(35 .3 % ) ;在3p1 4 .1 1 4 .3上D3s1 2 89的LOH率也较高 (33 .3 % )。 结论　 3号染色体可能在GBM的分子发病机制中发挥着重要作用 ,3p1 4 .1 1 4 .3上的D3s1 2 89和 3q2 2 2 3上的D3s1 569位点、3q2 4 2 7上的D3s1 61 4 D3s1 565位点间区域可能存在与GBM相关的肿瘤抑制基因     

Loss of heterozygosity in the tuberous sclerosis gene associated regions in adenocarcinoma of the lung accompanied by multiple atypical adenomatous hyperplasia

To investigate the potential allelic loss of tumor suppressor gene loci in the tuberous sclerosis complex (TSC)-associated regions located on the long arm of chromosome 9 (9q) and on the short arm of chromosome 16 (16p) in human lung carcinoma, we analyzed 21 paired normal and tumor DNAs with 11 polymorphic markers on the chromosomes. All tumors were adenocarcinoma of the lung, which included 9 adenocarcinomas with associated multiple atypical adenomatous hyperplasia (AAH). A precise microdissection technique followed by polymerase chain reaction (PCR) amplification to prevent under-evaluation of loss of heterozygosity (LOH) was used. Twelve of the 21 (57%) adenocarcinomas displayed LOH on 9q. Five of the 21 adenocarcinomas (24%) showed LOH at all informative loci on 9q, whereas 7 (33%) demonstrated partial LOH on 9q34. Among these 21, 5 (24%) showed partial LOH between D9S149 and D9S150, where TSC1 is located. The incidence of associated AAH was significantly higher in adenocarcinoma harboring a partial LOH in the TSC1-associated region (p = 0.0048). Twelve of the 21 (57%) adenocarcinomas displayed LOH on 16p. No significant differences in the clinico-pathological characteristics could be discerned between adenocarcinomas with and without LOH on 16p. When combining these data, a partial LOH at TSC1- and/or TSC2-associated loci was observed more frequently in cases with well-differentiated adenocarcinoma (p = 0.086) and associated AAH (p = 0.081). In conclusion, our results suggest that the TSC-associated regions are new candidate loci for tumor suppressor genes in lung adenocarcinoma, especially when it is accompanied by multiple AAH. Int. J. Cancer (Pred. Oncol.) 79:384–389, 1998. © 1998 Wiley-Liss, Inc.     

Allelic loss on chromosome 17 in human ovarian cancer

In order to identify a common region of deletion on chromosome 17 potentially containing a tumor-suppressor gene, 27 ovarian carcinomas and 3 ovarian tumors of low malignant potential (LMP) were examined for loss of heterozygosity (LOH) at 6 p arm and 10 q arm loci. Ninety percent of all tumors had deletions at one or more loci. On the p arm, there was a single near-common region of deletion on 17p 13.3 (D/7S30/ pYNZ22.1; 86% LOH), an intervening locus with a low LOH rate, and a more proximal locus on 17p11.2 (D/7S58/pEW301; 82% LOH) with a high LOH rate. In less aggressive tumors, LOH at Df 7S30 was not accompanied by LOH at p53. The q arm had a common region of deletion for high-stage carcinoma at D/7S579 (Mfd 188; 74% LOH) on q21, a locus tightly linked to the familial breast-ovarian-cancer syndrome (BRCAI) locus. D/7S579 was lost in all informative high-stage carcinomas and retained in all low-stage carcinomas and tumors of LMP. There may be at least 2 tumor-suppressor genes, an early-acting gene on the p arm and a gene on the q arm involved in tumor progression and metastasis.